package com.dp;

public class Solution48 {
    public int numDistinct(String s, String t) {
        int len1 = s.length();
        int len2 = t.length();
        int[][] dp =new int[len1+1][len2+1];
        for (int i = 0; i < len1; i++) {
            dp[i][0] = 1;
        }
        for (int i = 1; i <= len1; i++) {
            for (int j = 1; j <= len2; j++) {
                if (s.charAt(i-1)==t.charAt(j-1)) {
                    dp[i][j] = dp[i-1][j] + dp[i-1][j-1];
                } else {
                    dp[i][j] = dp[i-1][j];
                }
            }
        }
        return dp[len1][len2];
    }
}
